The late sodium current (INaL) is a sustained component of the fast Na+ current of cardiac myocytes and neurons. Many common neurological and cardiac conditions are associated with abnormal (INaL) enhancement, which contributes to the pathogenisis of both electrical and contactile dysfunction in mammals. See, for example, Pathophysiology and Pharmacology of the Cardiac “Late Sodium Current”, Pharmacology and Therapeutics 119 (2008) 326-339. Accordingly, pharmaceutical compounds that selectively inhibit (INaL) in mammals are useful in treating such disease states.
One example of a selective inhibitor of (INaL) is RANEXA®, a compound approved by the FDA for the treatment of chronic stable angina pectoris. RANEXA® has also been shown to be useful for the treatment of a variety of cardiovascular diseases, including ischemia, reperfusion injury, arrhythmia and unstable angina, and also for the treatment of diabetes. It would be desirable to provide novel compounds that selectively inhibit (INaL) in mammals and that have the same spectrum of activity as RANEXA®, but with a lower potential for blocking the potassium hERG channel.